21655205632 has 36 divisors (see below), whose sum is σ = 44145543456. Its totient is φ = 10597222400.

The previous prime is 21655205573. The next prime is 21655205647. The reversal of 21655205632 is 23650255612.

It is a junction number, because it is equal to n+sod(n) for n = 21655205591 and 21655205600.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 887869 + ... + 911932.

It is an arithmetic number, because the mean of its divisors is an integer number (1226265096).

Almost surely, 2^21655205632 is an apocalyptic number.

It is an amenable number.

21655205632 is an abundant number, since it is smaller than the sum of its proper divisors (22490337824).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21655205632 is an equidigital number, since it uses as much as digits as its factorization.

21655205632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1799864 (or 1799850 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 37.

The spelling of 21655205632 in words is "twenty-one billion, six hundred fifty-five million, two hundred five thousand, six hundred thirty-two".